1. Field
The present invention relates to liquid crystal display devices each having liquid crystal sealed between a color filter and a thin film transistor (TFT) substrate.
2. Description of Related Art
A color filter for use in a liquid crystal display device includes, on a substrate, colored layers of three colors, that is, red, green, and blue, and black matrixes, and the colored layers form pixels, and the black matrixes are provided between each pixel for blocking light. A TFT substrate having a plurality of thin film transistors (including pixel electrodes, switching elements formed of a semiconductor, and insulating film layers), and a source wiring and a gate wiring, is provided so as to oppose the color filter. Liquid crystal is sealed between the color filter and the TFT substrate.
In a process of producing the color filter, patterning is performed in a photolithography method to form the colored layers and the black matrixes. At this time, an exposure method (hereinafter, referred to as a “small mask continuous exposure method”) using a plurality of small photomasks may be used.
FIG. 6 is a schematic diagram illustrating an exposure method used in the process of producing a color filter, and illustrating the small mask continuous exposure method.
In an exposure device for use in the small mask exposure method, a plurality of exposure heads 90 each having a mask smaller than a substrate 94 are positioned so as to be aligned in a plurality of rows. The exposure heads 90 in a row are positioned between adjacent exposure heads 90 in another row without space such that pitches between the mask patterns formed on each photomask become uniform.
An exposure process is repeated multiple times, while the substrate 94 having the photoresist applied thereto is being conveyed in the Y-axis positive direction (the direction indicated by an arrow in the drawings) relative to the plurality of exposure heads 90 aligned as described above, so that pattern can be formed over the entire surface of the substrate 94 through baking